‘I’ve already told you. The Agency is the Agency, and BS is BS, and they are fighting for control of the thing in your head and mine. You need to wake up. You have everything to lose, my dear. Your life is just starting. But I’ve nothing to lose. I was wandering in a fog, in a darkness, and I’m ever so much better now. I don’t want to descend to a dribbling mess, I don’t want people to pity me and wipe my bottom out of kindness, I don’t want to forget how to speak or think. I’ll deal with any devil you like to avoid that fate. I expect that’s a problem for you and I’ll understand if we can’t be friends any more. I’ll find another dog-groomer, and you, well, you’ll be fine without me. You only ever came to see me because of my sister, and I don’t blame you for that. Let’s shake hands and be done.’

I stop and stare at her. She is trying to get up off the mat, but it’s a wobbly surface and she’s having trouble finding her balance. Instinctively, I step forward and give her a hand up. We stand looking at each other. There’s a rumpus in my head. My loud heart. But she has tears in her eyes.

‘It’s OK,’ I say faintly. ‘I’m not angry with you, it’s fine, I get it. Just tell me one thing. What did you mean, it grows into your skull?’

‘The treatment. It’s not a drug, it’s a therapeutic engine. After it implants itself, it grows across your skull. Your whole head acts like a receiver and your thought patterns can be accessed remotely. It’s how we do what we do, my dear. You and I.’

For no rational reason, I put my hands to my headscarf.

‘It made my hair fall out.’

‘It grows back, Charlie. It grows back.’

‘What about O? You don’t seem worried. Why are you not worried?’

‘My sister can take care of herself,’ Daphne says, and a kind of bleakness passes across her face. ‘I’ve never known anyone to get the better of her. She’s probably just lying low.’

I don’t like the sound of that. Lying low, or lying horizontal? A chill goes down my neck. I’ve dreamed with Martin Elstree. I know what he’s capable of. The woman he butchered in that dream was his boss, and he used power tools to get power over her.

Well, if there’s one thing you can say for sure about O, it’s that she’s bossy.

* * *